Tag Archives: electron volts

Possible evidence for dark matter particle presented at UCLA physics symposium

Dark matter, the mysterious substance estimated to make up approximately more than one-quarter of the mass of the universe, is crucial to the formation of galaxies, stars and even life but has so far eluded direct observation.

At a recent UCLA symposium attended by 190 scientists from around the world, physicists presented several analyses that participants interpreted to imply the existence of a dark matter particle. (more…)

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Foundations of Carbon-Based Life Leave Little Room for Error

Life as we know it is based upon the elements of carbon and oxygen. Now a team of physicists, including one from North Carolina State University, is looking at the conditions necessary to the formation of those two elements in the universe. They’ve found that when it comes to supporting life, the universe leaves very little margin for error.

Both carbon and oxygen are produced when helium burns inside of giant red stars. Carbon-12, an essential element we’re all made of, can only form when three alpha particles, or helium-4 nuclei, combine in a very specific way.  The key to formation is an excited state of carbon-12 known as the Hoyle state, and it has a very specific energy – measured at 379 keV (or 379,000 electron volts) above the energy of three alpha particles. Oxygen is produced by the combination of another alpha particle and carbon. (more…)

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A Cyclotron’s Long Journey Home

One of the world’s first working circular particle accelerators returns to Berkeley Lab—75 years later.

Seventy-five years after one of the world’s first working cyclotrons was handed to the London Science Museum, it has returned to its birthplace in the Berkeley hills, where the man who invented it, Ernest O. Lawrence, helped launch the field of modern particle physics as well as the national laboratory that would bear his name, Lawrence Berkeley National Laboratory.

On Jan. 9, 1932 the brass cyclotron—which measures 26 inches from end to end and whose accelerating chamber measures just 11 inches in diameter—was successfully used to boost protons to energies of 1.22 million electron volts. Its return to Berkeley Lab caps a decades-long saga in which various parties endeavored to secure the cyclotron’s return from London, but the persistence of Pamela Patterson, who chronicles Berkeley Lab’s history as managing editor of its website, finally paid off. (more…)

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State-of-the-Art Beams from Table-Top Accelerators

Berkeley Lab’s lead in laser plasma acceleration research continues with new benchmarks for electron beam quality

Part One: Focusing in on beam focus

The rapidly evolving technology of laser plasma accelerators (LPAs) – called “table-top accelerators” because their length can be measured in centimeters instead of kilometers – promises a new breed of machines, far less expensive and with far less impact on the land and the environment than today’s conventional accelerators.

Future LPAs offer not only compact high-energy colliders for fundamental physics but diminutive light sources as well. These will probe chemical reactions, from artificial photosynthesis to “green catalysis”; unique biological structures, inaccessible to other forms of microscopy yet essential to understanding life and health; and new materials, including low-temperature superconductors, topological insulators, spintronics devices, and graphene nanostructures, which will revolutionize the electronics industry. With intensely bright beams spanning the spectrum from microwaves to gamma rays, table-top accelerators will open new vistas of science. (more…)

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What’s Happening with the Higgs Boson

Berkeley Lab scientists, major contributors to the ATLAS experiment at the Large Hadron Collider, explain what the excitement is about

CERN, the European Organization for Nuclear Research headquartered in Geneva, Switzerland, will hold a seminar early in the morning on July 4 to announce the latest results from ATLAS and CMS, two major experiments at the Large Hadron Collider (LHC) that are searching for the Higgs boson. Both experimental teams are working down to the wire to finish analyzing their data, and to determine exactly what can be said about what they’ve found.

“We do not yet know what will be shown on July 4th,” says Ian Hinchliffe, a theoretical physicist in the Physics Division at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), who heads the Lab’s participation in the ATLAS experiment. “I have seen many conjectures on the blogs about what will be shown: these are idle speculation. Things are moving very fast this week, and it’s an exciting time at CERN. Many years of hard work are coming to fruition.” (more…)

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